Archaeologists have discovered the first unlooted royal tomb of the Wari empire, a pre-Inca civilization that covered what’s now western Peru from 700 to 1000.

A team led by Milosz Giersz of the University of Warsaw dug through rubble at a Wari site near Peru’s northern coast last September and entered a ceremonial room that contained a stone throne. There they found more than 1,000 artifacts, including gold and silver jewelry and bronze axes. A main chamber contained 60 human bodies buried in...